OAKLAND, Calif. (AP)  An Oakland homicide detective facing discipline for letting a girlfriend transcribe recorded witness interviews for him on 10 cases won’t be charged criminally, a Northern California district attorney announced Thursday.

Sgt. Mike Gantt was placed on paid leave several weeks ago after the scandal-plagued department’s internal affairs unit opened an investigation of him. The investigation comes amid a growing sex scandal involving a number of officers connected to the 18-year-old daughter of an Oakland police dispatcher.

Alameda County District Nancy O’Malley said there’s no law against detectives letting another person transcribe their witness recordings. The prosecutor said Gantt still faces internal discipline. O’Malley said none of the 10 homicide and attempted homicide cases should be jeopardized because of Gantt’s actions.

An Oakland police spokeswoman said the investigation is ongoing and declined further comment. Gantt was fired more than 12 years ago for interfering with a friend’s rape investigation. But Gantt won his job back in 2004 after appealing his decision to an arbitrator.

Gantt’s attorney, Mike Rains, didn’t return a call Thursday.

Gantt wasn’t implicated in the sex scandal, but his disciplinary case added to the woes of the beleaguered department. The department cycled through three chiefs in nine days before the city’s mayor put the city administrator in charge of the police on Friday.

In media interviews, the teen described herself as a sex worker. She said she had sex with as many as two dozen area police officers, most with the Oakland Police Department, and in return received protection and inside information on prostitution investigations. The woman said three officers had sex with her when she was a minor, incidents being investigated as sexual exploitation of a minor. The Associated Press doesn’t generally identify victims of sex crimes.

So far, two Oakland officers have resigned and three others have been placed on paid leave pending an internal affairs investigation. Several other officers have been placed on administrative leave at other Bay Area law enforcement agencies as well.